Cool idea for a puzzle game. I really like the movement of the ghost. I wish there was more room for him to move because it feels good to fly around with him. Very smooth with a pleasing amount of acceleration and speed to his movement. Did you make the music? I enjoyed the background track.
Sometimes, I would die from something I didn't see coming and have to restart the whole level which was a bit frustrating. I think it was the 5th or 6th level (the one where you are introduced to the spinning platforms) and, near the end, the button I pressed killed me and I don't know what caused it. Apparently, I'm supposed to ignore it? Because I saw I could just go in the mirror with the ghost without having to press the switch. There was also one on the (I think) 7th level where your press a switch to make the wall come out so you can reach another switch. But the wall came out so fast and unexpectantly that I had to restart the whole level over because it killed me. It was one of the longer levels, too.
Overall, I liked the game. Telegraphing the hazards would be helpful. The puzzles weren't too difficult, but were decently designed and were mostly intuitive besides the few surprise hazards I mentioned. Nice job!